An electronic device normally contains an electronic circuit which is provided with one or more electronic power components, for example a MOSFET, a power diode or the like. Such a power component also generates considerable heat loss in intended use, the heat loss needing to be dissipated from the appliance's housing in order to avoid overheating the circuit.
To create good dissipation of the heat loss, it is usual to mount the device on a, in particular, metal heat sink. Good heat transfer from the device to this heat sink is achieved by virtue of a carrier plate fitted with the power component(s) being integrated directly into the appliance's housing.
In this context, the carrier plate is expediently provided in a housing baseplate which, in the mounted state, bears directly against a bearing face of the heat sink. Especially since the thermal connection between the carrier plate and the heat sink is all the better the greater the evenness with which and the larger the area over which the carrier plate rests on the heat sink, the device is usually screwed to the heat sink, as a result of which the carrier plate is pressed against the bearing face of the heat sink.
To produce this screw joint, clips are frequently attached to the appliance's housing which protrude beyond said housing, particularly in the housing's longitudinal direction. The design of these clips means that they are at a relatively great distance from the center of gravity of the carrier plate. Thus, the fixing points at which the device is screwed to the heat sink are also at a relatively great distance from the carrier plate, as a result of which the prestress produced by the screw joint is transferred to the carrier plate only unfavorably and with a high level of loss.
The unfavorable energy transmission path results in high torsional loading on the housing, which arises to an increased degree particularly at the junction between the clips and the housing and in the area surrounding the edges of the carrier plate. These material stresses mean that the housing and/or the carrier plate can become damaged and—in the most unfavorable case—can even break.
To overcome the material distortions, the carrier plate has to date been soldered flat to a metal mounting plate then in turn screwed to the heat sink. However, soldering the carrier plate onto the mounting plate disadvantageously requires an additional and time-consuming production step. Furthermore, the mounting plate is a supplementary part of the device which firstly increases the manufacturing costs for the device and secondly increases the appliance's physical volume.